A novel low loss Nd2CaSnO6 microwave dielectric ceramic with double perovskite structure.

• ① A novel Nd 2 CaSnO 6 microwave dielectric ceramic was first discovered: ε r = 20.65, Q × f = 27,523 GHz, and τ f = –36.0 ppm/°C. • ② We analyzed the relationship between Raman spectroscopy and microwave dielectric properties. • ③ TEM analysis confirmed the double perovskite structure of Nd 2 CaSnO 6 ceramics. • ④ SEM images revealed the microstructure of the ceramic grains, with the maximum relative density reaching 97.5 %. This study elucidates the synthesis of a new class of Nd 2 CaSnO 6 microwave dielectric ceramics employing the conventional solid-phase method. X-ray diffraction (XRD) patterns and Rietveld refinement analysis revealed that the Nd 2 CaSnO 6 material crystallized into a single phase with an P21/n (14) space group. The double perovskite structure Nd 2 CaSnO 6 ceramics was confirmed through transmission electron microscopy (TEM), the structure exhibits a layered arrangement that is orderly. The internal microstructure was characterized using SEM, which showed that the sample's relative density reached 97.5 %. We discuss the correlation between FWHM and Q × f value of the Raman matrix at the Raman shift of 650.1 cm–1. Additionally, the main factors affecting the dielectric constant were analyzed, including density, secondary phase and porosity changes, etc. The ceramics exhibited remarkable microwave dielectric properties (ε r = 20.65, Q × f = 27523 GHz, and τ f = –36.0 ppm/ °C) when sintered at 1390 °C, indicating their potential as a microwave dielectric material. [Display omitted] [ABSTRACT FROM AUTHOR]